Upon starting of the engine at the time of the transition from an electrically driven (EV) mode to hybrid electric vehicle (HEV) mode, such a conventional technology Is known in which the transmission torque capacity of a second clutch will be lowered than a torque of motor/generator for starting the engine (see Japanese Laid-Open Patent Application Publication No. 2007-126091, for example).
However, when the vehicle speed is lower than a self-sustainable rotation speed of engine and the second clutch cannot be operated with slip, once the engine would be started, there is a problem of given a sense of discomfort to the driver.